Browse Prior Art Database

Removable Multichip Module Cap

IP.com Disclosure Number: IPCOM000088393D
Original Publication Date: 1977-Jun-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Jumbeck, GI: AUTHOR

Abstract

The cap of a multichip module (MCM) is made removable and replaceable.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 73% of the total text.

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Removable Multichip Module Cap

The cap of a multichip module (MCM) is made removable and replaceable.

Integrated-circuit chips C of module 1 (Fig. 1) are bonded to the surface of a multilayer printed-circuit ceramic substrate S. Chips C are surrounded by a suitable metallic ring 2, e.g., Ni-Fe affixed to the surface of S. A flexible similar metallic foil cover or cap 3, having a cantilever-like tab extension E, is seam- welded to the periphery of the ring so as to hermetically seal chips C. To remove cover 3, the extension E is Inserted into the slot 4 located on the shaft 5 of cap removal key 6. In this manner, as the knob 7 rotates, cap 3 "breaks" away from ring 2 and is wrapped about the shaft 5. Cap 3 may be scored to facilitate removal. To re-cover module 1, the weld area of ring 2 is vacuum-ground and a new foil cap is seam-welded to ring 2. Cover 3, and particularly its extension E, also provides additional heat-sink capability to module 1.

In Fig. 2, ring 2' is substantially planar with the surface of module 1'. The surface area of ring 2' is enlarged to accommodate different size flange caps having uniform heights. For example, originally module 1' is covered by smaller cap 31 (shown in phantom outline), which is sealed by its flange onto an innermost region of ring 2'. If it becomes necessary to remove cap 31, i.e., because of rework of a chip C' of module 1', then module 1' may be subsequently re-covered by intermediate size cap 32, the flange of which...